All natural ecosystems yield economically valuable services, e.g. production of food and medicines, regulation of climate, provision of productive soils and clean water, opportunities for recreation, maintenance of cultural heritage, etc. Ecosystem degradation undermines the provision of vital goods and services, with considerable economic and social consequences. Harmful effects tend to be borne disproportionately by the poor, who are less able to access or afford alternatives when ecosystem services are lost. In order to influence policy, and conserve important resources, people must know how to put a value on the services ecosystems provide, and communicate those results effectively.